Condensation targeter: the integration of a thermal and moisture model

This paper describes a design tool, 'Condensation Targeter', for assessing condensation risk in dwellings and the effect of remedial measures thereon. The BREDEM energy model is augmented by a moisture model to determine mean internal relative humidity (MIRH). This measure of condensation risk is calculated for two zones in a dwelling from mean internal temperatures, moisture generation and ventilation rates. Primary input data relate to occupancy (fuel expenditure and moisture production) and dwelling characteristics (thermal and ventilation). MIRH results are presented as a function of space heating input for an example dwelling with remedial measures applied (insulation and extract fans). The constraints imposed by household income and the implications for condensation risk are discussed. Comparisons between model predictions and monitored results are discussed as is the sensitivity of predictions to the accuracy of input data.